Detailed Description

Generic 4-vector.

Interpretation of its content depends on accessors used: it's much simpler to do this than to distinguish between space and momentum vectors via the type system (especially given the need for backward compatibility with HepMC2). Be sensible and don't call energy functions on spatial vectors! To avoid duplication, most definitions are only implemented on the spatial function names, with the energy-momentum functions as aliases.

This is not intended to be a fully featured 4-vector, but does contain the majority of common non-boosting functionality, as well as a few support operations on 4-vectors.

The implementations in this class are fully inlined.

Examples: basic_tree.cc.

Definition at line 35 of file FourVector.h.

#include <FourVector.h>

Public Member Functions
	FourVector ()
	Default constructor.
	FourVector (double xx, double yy, double zz, double ee)
	Sets all FourVector fields.
	FourVector (const FourVector &v)
	Copy constructor.
Component accessors
void	set (double x1, double x2, double x3, double x4)
	Set all FourVector fields, in order x,y,z,t.
double	x () const
	x-component of position/displacement
void	set_x (double xx)
	Set x-component of position/displacement.
void	setX (double xx)
double	y () const
	y-component of position/displacement
void	set_y (double yy)
	Set y-component of position/displacement.
void	setY (double yy)
double	z () const
	z-component of position/displacement
void	set_z (double zz)
	Set z-component of position/displacement.
void	setZ (double zz)
double	t () const
	Time component of position/displacement.
void	set_t (double tt)
	Set time component of position/displacement.
void	setT (double tt)
double	px () const
	x-component of momentum
void	set_px (double pxx)
	Set x-component of momentum.
void	setPx (double pxx)
double	py () const
	y-component of momentum
void	set_py (double pyy)
	Set y-component of momentum.
void	setPy (double pyy)
double	pz () const
	z-component of momentum
void	set_pz (double pzz)
	Set z-component of momentum.
void	setPz (double pzz)
double	e () const
	Energy component of momentum.
void	set_e (double ee)
	Set energy component of momentum.
void	setE (double ee)
Computed properties
double	length2 () const
	Squared magnitude of (x, y, z) 3-vector.
double	length () const
	Magnitude of spatial (x, y, z) 3-vector.
double	perp2 () const
	Squared magnitude of (x, y) vector.
double	perp () const
	Magnitude of (x, y) vector.
double	interval () const
	Spacetime invariant interval s^2 = t^2 - x^2 - y^2 - z^2.
double	p3mod2 () const
	Squared magnitude of p3 = (px, py, pz) vector.
double	p3mod () const
	Magnitude of p3 = (px, py, pz) vector.
double	pt2 () const
	Squared transverse momentum px^2 + py^2.
double	pt () const
	Transverse momentum.
double	m2 () const
	Squared invariant mass m^2 = E^2 - px^2 - py^2 - pz^2.
double	m () const
	Invariant mass. Returns -sqrt(-m) if e^2 - P^2 is negative.
double	phi () const
	Azimuthal angle.
double	theta () const
	Polar angle w.r.t. z direction.
double	eta () const
	Pseudorapidity.
double	rap () const
	Rapidity.
double	abs_eta () const
	Absolute pseudorapidity.
double	abs_rap () const
	Absolute rapidity.
double	pseudoRapidity () const
Comparisons to another FourVector
bool	is_zero () const
	Check if the length of this vertex is zero.
double	delta_phi (const FourVector &v) const
	Signed azimuthal angle separation in [-pi, pi].
double	delta_eta (const FourVector &v) const
	Pseudorapidity separation.
double	delta_rap (const FourVector &v) const
	Rapidity separation.
double	delta_r2_eta (const FourVector &v) const
	R_eta^2-distance separation dR^2 = dphi^2 + deta^2.
double	delta_r_eta (const FourVector &v) const
	R_eta-distance separation dR = sqrt(dphi^2 + deta^2).
double	delta_r2_rap (const FourVector &v) const
	R_rap^2-distance separation dR^2 = dphi^2 + drap^2.
double	delta_r_rap (const FourVector &v) const
	R-rap-distance separation dR = sqrt(dphi^2 + drap^2).

Operators
double	m_v1
	px or x. Interpretation depends on accessors used
double	m_v2
	py or y. Interpretation depends on accessors used
double	m_v3
	pz or z. Interpretation depends on accessors used
double	m_v4
	e or t. Interpretation depends on accessors used
bool	operator== (const FourVector &rhs) const
	Equality.
bool	operator!= (const FourVector &rhs) const
	Inequality.
FourVector	operator+ (const FourVector &rhs) const
	Arithmetic operator +.
FourVector	operator- (const FourVector &rhs) const
	Arithmetic operator -.
FourVector	operator* (const double rhs) const
	Arithmetic operator * by scalar.
FourVector	operator/ (const double rhs) const
	Arithmetic operator / by scalar.
void	operator+= (const FourVector &rhs)
	Arithmetic operator +=.
void	operator-= (const FourVector &rhs)
	Arithmetic operator -=.
void	operator*= (const double rhs)
	Arithmetic operator *= by scalar.
void	operator/= (const double rhs)
	Arithmetic operator /= by scalar.
static const FourVector &	ZERO_VECTOR ()
	Static null FourVector = (0,0,0,0).

Constructor & Destructor Documentation

◆ FourVector() [1/3]

FourVector ( )

inline

Default constructor.

Definition at line 39 of file FourVector.h.

References m_v1, m_v2, m_v3, and m_v4.

◆ FourVector() [2/3]

FourVector	(	double	xx,
		double	yy,
		double	zz,
		double	ee )

inline

Sets all FourVector fields.

Definition at line 42 of file FourVector.h.

References m_v1, m_v2, m_v3, and m_v4.

◆ FourVector() [3/3]

FourVector ( const FourVector & v )

inline

Copy constructor.

Definition at line 45 of file FourVector.h.

References FourVector(), m_v1, m_v2, m_v3, and m_v4.

Member Function Documentation

◆ abs_eta()

double abs_eta ( ) const

inline

Absolute pseudorapidity.

Definition at line 159 of file FourVector.h.

References eta().

◆ abs_rap()

double abs_rap ( ) const

inline

Absolute rapidity.

Definition at line 161 of file FourVector.h.

References rap().

◆ delta_eta()

double delta_eta ( const FourVector & v ) const

inline

Pseudorapidity separation.

Definition at line 186 of file FourVector.h.

References eta(), and FourVector().

◆ delta_phi()

double delta_phi ( const FourVector & v ) const

inline

Signed azimuthal angle separation in [-pi, pi].

Definition at line 177 of file FourVector.h.

References FourVector(), M_PI, and phi().

◆ delta_r2_eta()

double delta_r2_eta ( const FourVector & v ) const

inline

R_eta^2-distance separation dR^2 = dphi^2 + deta^2.

Definition at line 192 of file FourVector.h.

References delta_eta(), delta_phi(), and FourVector().

◆ delta_r2_rap()

double delta_r2_rap ( const FourVector & v ) const

inline

R_rap^2-distance separation dR^2 = dphi^2 + drap^2.

Definition at line 202 of file FourVector.h.

References delta_phi(), delta_rap(), and FourVector().

◆ delta_r_eta()

double delta_r_eta ( const FourVector & v ) const

inline

R_eta-distance separation dR = sqrt(dphi^2 + deta^2).

Definition at line 197 of file FourVector.h.

References delta_r2_eta(), and FourVector().

◆ delta_r_rap()

double delta_r_rap ( const FourVector & v ) const

inline

R-rap-distance separation dR = sqrt(dphi^2 + drap^2).

Definition at line 207 of file FourVector.h.

References delta_r2_rap(), and FourVector().

◆ delta_rap()

double delta_rap ( const FourVector & v ) const

inline

Rapidity separation.

Definition at line 189 of file FourVector.h.

References FourVector(), and rap().

◆ e()

double e ( ) const

inline

Energy component of momentum.

Definition at line 112 of file FourVector.h.

References t().

◆ eta()

double eta ( ) const

inline

Pseudorapidity.

Definition at line 155 of file FourVector.h.

References p3mod(), and pz().

◆ interval()

double interval ( ) const

inline

Spacetime invariant interval s^2 = t^2 - x^2 - y^2 - z^2.

Definition at line 133 of file FourVector.h.

References length2(), and t().

◆ is_zero()

bool is_zero ( ) const

inline

Check if the length of this vertex is zero.

Definition at line 174 of file FourVector.h.

References t(), x(), y(), and z().

◆ length()

double length ( ) const

inline

Magnitude of spatial (x, y, z) 3-vector.

Definition at line 127 of file FourVector.h.

References length2().

◆ length2()

double length2 ( ) const

inline

Squared magnitude of (x, y, z) 3-vector.

Definition at line 125 of file FourVector.h.

References x(), y(), and z().

◆ m()

double m ( ) const

inline

Invariant mass. Returns -sqrt(-m) if e^2 - P^2 is negative.

Definition at line 146 of file FourVector.h.

References m2().

◆ m2()

double m2 ( ) const

inline

Squared invariant mass m^2 = E^2 - px^2 - py^2 - pz^2.

Definition at line 144 of file FourVector.h.

References interval().

◆ operator!=()

bool operator!= ( const FourVector & rhs ) const

inline

Inequality.

Definition at line 222 of file FourVector.h.

References FourVector().

◆ operator*()

FourVector operator* ( const double rhs ) const

inline

Arithmetic operator * by scalar.

Definition at line 233 of file FourVector.h.

References FourVector(), t(), x(), y(), and z().

◆ operator*=()

void operator*= ( const double rhs )

inline

Arithmetic operator *= by scalar.

Definition at line 256 of file FourVector.h.

References setT(), setX(), setY(), setZ(), t(), x(), y(), and z().

◆ operator+()

FourVector operator+ ( const FourVector & rhs ) const

inline

Arithmetic operator +.

Definition at line 225 of file FourVector.h.

References FourVector(), t(), x(), y(), and z().

◆ operator+=()

void operator+= ( const FourVector & rhs )

inline

Arithmetic operator +=.

Definition at line 242 of file FourVector.h.

References FourVector(), setT(), setX(), setY(), setZ(), t(), x(), y(), and z().

◆ operator-()

FourVector operator- ( const FourVector & rhs ) const

inline

Arithmetic operator -.

Definition at line 229 of file FourVector.h.

References FourVector(), t(), x(), y(), and z().

◆ operator-=()

void operator-= ( const FourVector & rhs )

inline

Arithmetic operator -=.

Definition at line 249 of file FourVector.h.

References FourVector(), setT(), setX(), setY(), setZ(), t(), x(), y(), and z().

◆ operator/()

FourVector operator/ ( const double rhs ) const

inline

Arithmetic operator / by scalar.

Definition at line 237 of file FourVector.h.

References FourVector(), t(), x(), y(), and z().

◆ operator/=()

void operator/= ( const double rhs )

inline

Arithmetic operator /= by scalar.

Definition at line 263 of file FourVector.h.

References setT(), setX(), setY(), setZ(), t(), x(), y(), and z().

◆ operator==()

bool operator== ( const FourVector & rhs ) const

inline

Equality.

Definition at line 218 of file FourVector.h.

References FourVector(), t(), x(), y(), and z().

◆ p3mod()

double p3mod ( ) const

inline

Magnitude of p3 = (px, py, pz) vector.

Definition at line 138 of file FourVector.h.

References length().

◆ p3mod2()

double p3mod2 ( ) const

inline

Squared magnitude of p3 = (px, py, pz) vector.

Definition at line 136 of file FourVector.h.

References length2().

◆ perp()

double perp ( ) const

inline

Magnitude of (x, y) vector.

Definition at line 131 of file FourVector.h.

References perp2().

◆ perp2()

double perp2 ( ) const

inline

Squared magnitude of (x, y) vector.

Definition at line 129 of file FourVector.h.

References x(), and y().

◆ phi()

double phi ( ) const

inline

Azimuthal angle.

Definition at line 149 of file FourVector.h.

References x(), and y().

◆ pseudoRapidity()

double pseudoRapidity ( ) const

inline

Same as eta()

Deprecated: Prefer 'only one way to do it', and we don't have equivalent long names for e.g. pid, phi or eta

Definition at line 165 of file FourVector.h.

References eta().

◆ pt()

double pt ( ) const

inline

Transverse momentum.

Definition at line 142 of file FourVector.h.

References perp().

◆ pt2()

double pt2 ( ) const

inline

Squared transverse momentum px^2 + py^2.

Definition at line 140 of file FourVector.h.

References perp2().

◆ px()

double px ( ) const

inline

x-component of momentum

Definition at line 91 of file FourVector.h.

References x().

◆ py()

double py ( ) const

inline

y-component of momentum

Definition at line 98 of file FourVector.h.

References y().

◆ pz()

double pz ( ) const

inline

z-component of momentum

Definition at line 105 of file FourVector.h.

References z().

◆ rap()

double rap ( ) const

inline

Rapidity.

Definition at line 157 of file FourVector.h.

References e(), and pz().

◆ set()

void set	(	double	x1,
		double	x2,
		double	x3,
		double	x4 )

inline

Set all FourVector fields, in order x,y,z,t.

Definition at line 53 of file FourVector.h.

References m_v1, m_v2, m_v3, and m_v4.

◆ set_e()

void set_e ( double ee )

inline

Set energy component of momentum.

Definition at line 114 of file FourVector.h.

References set_t().

◆ set_px()

void set_px ( double pxx )

inline

Set x-component of momentum.

Definition at line 93 of file FourVector.h.

References set_x().

◆ set_py()

void set_py ( double pyy )

inline

Set y-component of momentum.

Definition at line 100 of file FourVector.h.

References set_y().

◆ set_pz()

void set_pz ( double pzz )

inline

Set z-component of momentum.

Definition at line 107 of file FourVector.h.

References set_z().

◆ set_t()

void set_t ( double tt )

inline

Set time component of position/displacement.

Definition at line 85 of file FourVector.h.

References m_v4.

◆ set_x()

void set_x ( double xx )

inline

Set x-component of position/displacement.

Definition at line 64 of file FourVector.h.

References m_v1.

◆ set_y()

void set_y ( double yy )

inline

Set y-component of position/displacement.

Definition at line 71 of file FourVector.h.

References m_v2.

◆ set_z()

void set_z ( double zz )

inline

Set z-component of position/displacement.

Definition at line 78 of file FourVector.h.

References m_v3.

◆ setE()

void setE ( double ee )

inline

Deprecated: Prefer the HepMC-style set_y() function

Definition at line 116 of file FourVector.h.

References set_e().

◆ setPx()

void setPx ( double pxx )

inline

Deprecated: Prefer the HepMC-style set_px() function

Definition at line 95 of file FourVector.h.

References set_px().

◆ setPy()

void setPy ( double pyy )

inline

Deprecated: Prefer the HepMC-style set_py() function

Definition at line 102 of file FourVector.h.

References set_py().

◆ setPz()

void setPz ( double pzz )

inline

Deprecated: Prefer the HepMC-style set_pz() function

Definition at line 109 of file FourVector.h.

References set_pz().

◆ setT()

void setT ( double tt )

inline

Deprecated: Prefer the HepMC-style set_t() function

Definition at line 87 of file FourVector.h.

References set_t().

◆ setX()

void setX ( double xx )

inline

Deprecated: Prefer the HepMC-style set_x() function

Definition at line 66 of file FourVector.h.

References set_x().

◆ setY()

void setY ( double yy )

inline

Deprecated: Prefer the HepMC-style set_y() function

Definition at line 73 of file FourVector.h.

References set_y().

◆ setZ()

void setZ ( double zz )

inline

Deprecated: Prefer the HepMC-style set_z() function

Definition at line 80 of file FourVector.h.

References set_z().

◆ t()

double t ( ) const

inline

Time component of position/displacement.

Definition at line 83 of file FourVector.h.

References m_v4.

◆ theta()

double theta ( ) const

inline

Polar angle w.r.t. z direction.

Definition at line 151 of file FourVector.h.

References perp(), and z().

◆ x()

double x ( ) const

inline

x-component of position/displacement

Definition at line 62 of file FourVector.h.

References m_v1.

◆ y()

double y ( ) const

inline

y-component of position/displacement

Definition at line 69 of file FourVector.h.

References m_v2.

◆ z()

double z ( ) const

inline

z-component of position/displacement

Definition at line 76 of file FourVector.h.

References m_v3.

◆ ZERO_VECTOR()

const FourVector & ZERO_VECTOR ( )

inlinestatic

Static null FourVector = (0,0,0,0).

Definition at line 274 of file FourVector.h.

References FourVector().

Field Documentation

◆ m_v1

double m_v1

private

px or x. Interpretation depends on accessors used

Definition at line 282 of file FourVector.h.

◆ m_v2

double m_v2

private

py or y. Interpretation depends on accessors used

Definition at line 283 of file FourVector.h.

◆ m_v3

double m_v3

private

pz or z. Interpretation depends on accessors used

Definition at line 284 of file FourVector.h.

◆ m_v4

double m_v4

private

e or t. Interpretation depends on accessors used

Definition at line 285 of file FourVector.h.

The documentation for this class was generated from the following file:

FourVector.h

Detailed Description

Public Member Functions

Operators

Constructor & Destructor Documentation

◆ FourVector() [1/3]

◆ FourVector() [2/3]

◆ FourVector() [3/3]

Member Function Documentation

◆ abs_eta()

◆ abs_rap()

◆ delta_eta()

◆ delta_phi()

◆ delta_r2_eta()

◆ delta_r2_rap()

◆ delta_r_eta()

◆ delta_r_rap()

◆ delta_rap()

◆ e()

◆ eta()

◆ interval()

◆ is_zero()

◆ length()

◆ length2()

◆ m()

◆ m2()

◆ operator!=()

◆ operator*()

◆ operator*=()

◆ operator+()

◆ operator+=()

◆ operator-()

◆ operator-=()

◆ operator/()

◆ operator/=()

◆ operator==()

◆ p3mod()

◆ p3mod2()

◆ perp()

◆ perp2()

◆ phi()

◆ pseudoRapidity()

◆ pt()

◆ pt2()

◆ px()

◆ py()

◆ pz()

◆ rap()

◆ set()

◆ set_e()

◆ set_px()

◆ set_py()

◆ set_pz()

◆ set_t()

◆ set_x()

◆ set_y()

◆ set_z()

◆ setE()

◆ setPx()

◆ setPy()

◆ setPz()

◆ setT()

◆ setX()

◆ setY()

◆ setZ()

◆ t()

◆ theta()

◆ x()

◆ y()

◆ z()

◆ ZERO_VECTOR()

Field Documentation

◆ m_v1

◆ m_v2

◆ m_v3

◆ m_v4